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Enhanced prediction of anisotropic deformation behavior using machine learning with data augmentation

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Journal of Magnesium and Alloys 2024年第1期12卷 186-196页

作者： Sujeong Byun Jinyeong Yu Seho Cheon Seong Ho Lee Sung Hyuk Park Taekyung Lee school of Mechanical Engineering Pusan National UniversityBusan 46241South Korea school of Materials Science and Engineering Kyungpook National UniversityDaegu 41566South Korea

Mg alloys possess an inherent plastic anisotropy owing to the selective activation of deformation mechanisms depending on the loading condition.This characteristic results in a diverse range of flow curves that vary with a deformation condition.This study proposes a novel approach for accurately predicting an anisotropic deformation behavior of wrought Mg alloys using machine learning(ML)with data augmentation.The developed model combines four key strategies from data science:learning the entire flow curves,generative adversarial networks(GAN),algorithm-driven hyperparameter tuning,and gated recurrent unit(GRU)architecture.The proposed model,namely GAN-aided GRU,was extensively evaluated for various predictive scenarios,such as interpolation,extrapolation,and a limited dataset size.The model exhibited significant predictability and improved generalizability for estimating the anisotropic compressive behavior of ZK60 Mg alloys under 11 annealing conditions and for three loading directions.The GAN-aided GRU results were superior to those of previous ML models and constitutive equations.The superior performance was attributed to hyperparameter optimization,GAN-based data augmentation,and the inherent predictivity of the GRU for extrapolation.As a first attempt to employ ML techniques other than artificial neural networks,this study proposes a novel perspective on predicting the anisotropic deformation behaviors of wrought Mg alloys.

关键词： Plastic anisotropy Compression Annealing Machine learning Data augmentation

Influence of contact curvature on frictional energy dissipation under varying tangential loads

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Friction 2024年第2期12卷 363-374页

作者： Sumin BAEK Seunghun BAEK school of Mechanical Engineering Pusan National UniversityPusan 46241Republic of Korea

This study investigates the effect of contact surface curvatures on the friction response under varying tangential loadings using a finite element(FE)model.The results showed that the geometry of the surface influences the contact force at the interface and reduces the friction effect through an unsteady distribution of the contact force.The relationship between the friction effect,excitation,and contact surface shape was also examined,revealing a linear inverse relationship between the friction and curvature.The findings provide a comprehensive understanding of the frictional interactions between elastic bodies and highlight the role of curvature as a design parameter for regulating the friction effect.

关键词： frictional contact curvelinear contact frictional energy dissipation contact curvature

TonEBP expression is essential in the IL-1β–induced migration and invasion of human A549 lung cancer cells

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Oncology Research 2024年第1期32卷 151-161页

作者： HEE JU SONG TAEHEE KIM HAN NA CHOI SOO JIN KIM SANG DO LEE Department of Physiology School of MedicineChungnam National UniversityDaejeon35015Korea

Lung cancer has the highest mortality rate among all cancers,in part because it readily metastasizes.The tumor microenvironment,comprising blood vessels,fibroblasts,immune cells,and macrophages[including tumor-associated macrophages(TAMs)],is closely related to cancer cell growth,migration,and invasion.TAMs secrete several cytokines,including interleukin(IL)-1β,which participate in cancer migration and invasion.p21-activated kinase 1(PAK1),an important signaling molecule,induces cell migration and invasion in several carcinomas.Tonicityresponsive enhancer-binding protein(TonEBP)is also known to participate in cancer cell growth,migration,and invasion.However,the mechanisms by which it increases lung cancer migration remain unclear.Therefore,in this study,we aimed to elucidate the mechanisms by which IL-1βand TonEBP affect lung cancer cell migration and invasion.We found that A549 cocultured-MΦ-secreted IL-1βinduced A549 cell migration and invasion via the PAK1 pathway.TonEBP deficiency reduced A549 cell migration and invasion and increased responsiveness to IL-1β–induced migration and invasion.PAK1 phosphorylation,which was promoted by IL-1β,was reduced when TonEBP was depleted.These results suggest that TonEBP plays an important role in IL-1βinduction and invasiveness of A549 cells via the PAK1 pathway.These findings could be valuable in identifying potential targets for lung cancer treatment.

关键词： Lung cancer TonEBP Tumor microenvironment Tumor-associated macrophage IL-1β

Overview of radar detection methods for low altitude targets in marine environments

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Journal of Systems Engineering and Electronics 2024年第1期35卷 1-13页

作者： YANG Yong YANG Boyu school of Electronic Science National University of Defense TechnologyChangsha 410073China

In this paper,a comprehensive overview of radar detection methods for low-altitude targets in maritime environments is presented,focusing on the challenges posed by sea clutter and multipath scattering.The performance of the radar detection methods under sea clutter,multipath,and combined conditions is categorized and summarized,and future research directions are outlined to enhance radar detection performance for low-altitude targets in maritime environments.

关键词： radar sea clutter multipath scattering detection low altitude target

Nutritional and lipid profile status of children with spinal muscular atrophy in China: A retrospective case-control study

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中华医学杂志(英文版) 2024年第10期137卷 1243-1245页

作者： Feng Yijie Wei Jia Yao Mei Jin Jianing Cui Yiqin Long Qi Chen Fei Hong Yi Zhou Dongming Hu Jingjing Chen Xiao Gao Feng Yuan Changzheng Mao Shanshan Department of Neurology Children’s Hospital Zhejiang University School of Medicine National Clinical Research Center for Child Health Hangzhou Zhejiang China Department of Infection Children’s Hospital Zhejiang University School of Medicine National Clinical Research Center for Child Health Hangzhou Zhejiang China Department of Nutrition Children’s Hospital Zhejiang University School of Medicine National Clinical Research Center for Child Health Hangzhou Zhejiang China Children’s Hospital Zhejiang University School of Medicine National Clinical Research Center for Child Health Hangzhou Zhejiang China school of Public Health Zhejiang University School of Medicine Hangzhou Zhejiang China Children’s Hospital School of Public Health Zhejiang University School of Medicine National Clinical Research Center for Child Health Hangzhou Zhejiang China

5q spinal muscular atrophy (5qSMA) is an autosomal recessive neuromuscular disorder caused by the lack of the survival motor neuron (SMN) protein encoded by the SMN1 gene, located at 5q11.2-q13.3.[1] The incidence is 1/10,000-1/6000 live births, and the mutation carrier rate in China is 1/42.[1] Spinal muscular atrophy (SMA) is mainly divided into four subtypes: SMA type I, II, III, and IV, based on the motor milestones ever achieved. Types I-III occur in children,[1] which often result in progressive muscular atrophy and weakness as well as multi-system dysfunction, including nutritional and metabolic issues.[2] Children with SMA may have hidden nutritional and lipid imbalances, despite normal body appearance and anthropometric measurements, making it difficult to detect early and intervene. Fewer studies have elucidated both the nutritional status and lipid metabolism in SMA patients,[2] especially in Asia, which may have some of the highest numbers of SMA patients in the world. To inform the development of targeted nutritional management strategies, this study aimed to investigate the nutritional status and serum lipid profile characteristics in children with SMA, based on a hospital-based case-control study in China. This study was approved by the Ethics Committee of Children's Hospital of Zhejiang University school of Medicine (No. 2019-IRB-171). Written informed consent was obtained from all the patients and their legal guardians.

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Highly Aligned Ternary Nanofiber Matrices Loaded with MXene Expedite Regeneration of Volumetric Muscle Loss

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Nano-Micro Letters 2024年第4期16卷 269-292页

作者： Moon Sung Kang Yeuni Yu Rowoon Park Hye Jin Heo Seok Hyun Lee Suck Won Hong Yun Hak Kim Dong‑Wook Han Department of Cogno‑Mechatronics Engineering College of Nanoscience and NanotechnologyPusan National UniversityBusan 46241Republic of Korea Medical Research Institute School of MedicinePusan National UniversityYangsan 50612Republic of Korea Department of Anatomy School of MedicinePusan National UniversityYangsan 50612Republic of Korea Engineering Research Center for Color‑Modulated Extra‑Sensory Perception Technology Pusan National UniversityBusan 46241Republic of Korea Department of Biomedical Informatics School of MedicinePusan National UniversityYangsan 50612Republic of Korea Periodontal Disease Signaling Network Research Center and Dental and Life Science Institute School of DentistryPusan National UniversityYangsan 50612Republic of Korea BIO‑IT Fusion Technology Research Institute Pusan National UniversityBusan 46241Republic of Korea Present Address:Osstem Implant Inc. Seoul 07789Republic of Korea

Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as a promising alternative.In this study,we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone)integrated with collagen and Ti_(3)C_(2)T_(x)MXene nanoparticles(NPs)(PCM matrices),and explored their myogenic potential for skeletal muscle tissue regeneration.The PCM matrices demonstrated favorable physicochemical properties,including structural uniformity,alignment,microporosity,and hydrophilicity.In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts.Moreover,in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury.Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices,leading to elevated intracellular Ca^(2+)levels in myoblasts through the activation of inducible nitric oxide synthase(i NOS)and serum/glucocorticoid regulated kinase 1(SGK1),ultimately promoting myogenic differentiation via the m TOR-AKT pathway.Additionally,upregulated i NOS and increased NO–contributed to myoblast proliferation and fiber fusion,thereby facilitating overall myoblast maturation.These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.

关键词： Ti_(3)C_(2)T_(x)MXene nanoparticle Ternary nanofibrous matrices Myogenesis Regeneration of volumetric muscle loss Next generation sequencing

Deciphering the role of rGO in tuning dielectric properties of Er_(2)O_(3)/ZnO/rGO nanocomposites synthesized via facile approach

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Journal of Rare Earths 2024年第3期42卷 578-585,I0006页

作者： Saiqa Hafeez Saima Perveen Muhammad Zarrar Khan Awab Hashmi Fahad Azad school of Natural Sciences(SNS) National University of Sciences and Technology(NUST)IslamabadPakistan Electronic and Magnetic Materials Laboratory School of Chemical and Materials Engineering(SCME)National University of Sciences and Technology(NUST)IslamabadPakistan

The present research investigated the effect of reduced graphene oxide(rGO) integration with assynthesized Er_(2)O_(3)/ZnO nanocomposites on dielectric properties. The samples were characterized by Xray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), diffuse reflectance spectroscopy(DRS), and energy dispersive spectroscopy(EDS). Complex impedance spectroscopy was utilized to characterize dielectric relaxation phenomena in Er_(2)O_(3)/ZnO and Er_(2)O_(3)/ZnO/rGO nanocomposites. All the samples exhibit single relaxation phenomena which are ascribed to grain boundaries. The addition of rGO to Er_(2)O_(3)/ZnO nanocomposite results in the enhancement of dielectric response due to increased local field intensity caused by the formation of conductinginsulating interfaces. Furthermore, the AC conductivity of the Er_(2)O_(3)/ZnO/rGO is increased at higher frequencies due to the presence of free charge carriers in rGO. At higher frequencies, Er_(2)O_(3)/ZnO/rGO nanocomposite with increased concentration of ZnO exhibits a more stable dielectric constant with extremely low dielectric loss. Hence, the inclusion of rGO in Er_(2)O_(3)/ZnO nanocomposites makes it a novel prospective candidate in the field of energy storage devices.

关键词： Erbium oxide(Er_(2)O_(3)) Rare earths Stable dielectric constant Impedance Polarization Grain boundaries

Improved Twin Support Vector Machine Algorithm and Applications in Classification Problems

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China Communications 2024年第5期21卷 261-279页

作者： Sun Yi Wang Zhouyang Beijing University of Posts and Telecommunications School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and Telecommunications International School

The distribution of data has a significant impact on the results of classification.When the distribution of one class is insignificant compared to the distribution of another class,data imbalance occurs.This will result in rising outlier values and noise.Therefore,the speed and performance of classification could be greatly affected.Given the above problems,this paper starts with the motivation and mathematical representing of classification,puts forward a new classification method based on the relationship between different classification formulations.Combined with the vector characteristics of the actual problem and the choice of matrix characteristics,we firstly analyze the orderly regression to introduce slack variables to solve the constraint problem of the lone point.Then we introduce the fuzzy factors to solve the problem of the gap between the isolated points on the basis of the support vector machine.We introduce the cost control to solve the problem of sample skew.Finally,based on the bi-boundary support vector machine,a twostep weight setting twin classifier is constructed.This can help to identify multitasks with feature-selected patterns without the need for additional optimizers,which solves the problem of large-scale classification that can’t deal effectively with the very low category distribution gap.

关键词： fuzzy ordered regression(OR) relaxing variables twin support vector machine

Elevated brain temperature under severe heat exposure impairs cortical motor activity and executive function

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Journal of Sport and Health Science 2024年第2期13卷 233-244页

作者： Xiang Ren Tan Mary C.Stephenson Sharifah Badriyah Alhadad Kelvin W.Z.Loh Tuck Wah Soong Jason K.W.Lee Ivan C.C.Low Health and Social Sciences Singapore Institute of TechnologySingapore 138683Singapore Human Potential Translational Research Programme Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117597Singapore Centre for Translational Magnetic Resonance Research Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117549Singapore Department of Physiology Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117593Singapore Heat Resilience and Performance Centre Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117510Singapore N.1 Institute for Health National University of SingaporeSingapore 117456Singapore Campus for Research Excellence and Technological Enterprise(CREATE) Singapore 138602Singapore

Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive function.While heat is a known physiological stressor,it is unclear how severe heat stress affects brain physiology and function.Methods:Eleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures(T_(re))attained 39.5℃,inducing exertional or passive hyperthermia,respectively.In a separate trial,blended ice was ingested before and during exercise as a cooling strategy.Data were compared to a control condition with seated rest(normothermic).Brain temperature(T_(br)),cerebral perfusion,and task-based brain activity were assessed using magnetic resonance imaging techniques.Results:T_(br)in motor cortex was found to be tightly regulated at rest(37.3℃±0.4℃(mean±SD))despite fluctuations in T_(re).With the development of hyperthermia,T_(br)increases and dovetails with the rising T_(re).Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks,implying a reduced central motor drive in hyperthermic participants(T_(re)=38.5℃±0.1℃).Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive hyperthermia.Executive function was poorer under a passive hyperthermic state,and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital cortex.Conversely,ingestion of blended ice before and during exercise alleviated the rise in both T_(re)and T_(bc)and mitigated heat-related neural perturbations.Conclusion:Severe heat exposure elevates T_(br),disrupts motor cortical activity and executive function,and this can lead to impairment of physical and cognitive performance.

关键词： Brain functional activity Cognition Heat stress Hyperthermia Motor function